1. Field of the Invention
This invention relates to a thermostat with load activation detection, and to a method of controlling an HVAC system utilizing load activation detection.
2. Description of the Prior Art
Thermostats used for controlling HVAC systems typically control relays in the HVAC systems to operate heating loads and cooling loads without confirming whether the heating unit or the cooling unit, as the case may be, has actually responded when activated by the thermostat. Without the ability to confirm activation of the load, prior art thermostats are unable either to make repeated attempts to activate the heating or cooling unit, or to signal an actual failure of control. Failure of control will result in heating or cooling not actually being performed when needed, or heating or cooling continuing when it is not wanted. Aside from being wasteful in the latter case, failure of control may result in the environmental temperature becoming uncomfortable.